A replicated, controlled study in 1986-1988 of two wheat fields in Oxfordshire, UK (Tew et al. 1992) found that conservation and unsprayed headlands were used more frequently by wood mice Apodemus sylvaticus than sprayed headlands and mid-field. Preference indices for wood mice were 6 for conservation headlands, 6-7 for unsprayed headlands, 2-4 for sprayed plots and 3 for mid-field. Mice showed a significant preference for the mid-field over sprayed headlands. Conservation and unsprayed headland plots contained significantly higher densities of black-grass Alopecurus myosuroides, wild oats Avena spp., sterile brome Bromus sterilis and forget-me-not Myosotis arvensis. Abundance did not differ between the sprayed headland and mid-field for any weed species. In 1986, four of 15 orders of invertebrate were significantly more abundant in unsprayed than sprayed headlands (springtails (Collembola): 6 vs 1 m², true bugs (Hemiptera): 23 vs 8 m², flies (Diptera): 142 vs 24 m², parasitoid wasps (Parasitica): 18 vs 5 m²). In 1987 there was no significant difference between invertebrate abundance in sprayed, unsprayed or conservation headland plots. In one field, alternate plots (20 x 10 m) along the headland were either conventionally sprayed or unsprayed, or in 1987 conservation headland plots. Vegetation was sampled in 5-10 quadrats (0.25 x 0.25 m) in 8-11 plots/treatment in July. In the conventionally sprayed control field, plants were sampled in quadrats of 0.06 m² at 1, 5 and 8 m from the hedge and in the centre of the field. Invertebrates were sampled at 3-5 random positions within 3-8 plots/treatment using a D- Vac sampler in July 1986-1987. Wood mice were radio-tracked at 10 min intervals at night in May-August.